STEP 1: DIGITIZING
1. digitize (PLINE) as closed entity (end with C)
if reconstructing upper shape:
2. Draw midline based on vessel diameter.
Set COORDS to 2, to measure distance from rim (radius) and angle (180), and use F8 (ORTHO)
to have straight lines.
PLINE: start on point 1; move left watching
coordinates (lower left) and <click> when coordinates show 5<180 (if
radius=5) (see point 2), then continue to draw midline down till point 3, <click>
& <enter>.
If not reconstructing mouth shape: finish with a short horizontal line indicating the plane of
the sherd, and the hatch the entity.
Continue to step 2